1. Field of the Invention
The present invention generally relates to a system and method which is adapted for use with multiple satellite-based distribution networks. More particularly, the invention is directed to an apparatus and method for processing content signals received from a plurality of different, and possibly dissimilar, signal sources, such as different satellite networks.
2. Description of the Related Art
Conventional communications systems may include a receiver for receiving and processing transmitted waveforms. For example, in a satellite communications system, the receiver may include a small satellite dish connected by a cable to a set-top box (STB) or an integrated receiver-decoder (IRD), both being referred to generally herein as an STB, which are used as interchangeable terms in the art. The satellite dish is aimed toward the satellite, and the STB is connected to the user's television in a similar fashion to a conventional cable-TV decoder.
A micro-controller controls the overall operation of the STB, including the selection of parameters, the set-up and control of components, channel selection, viewer access to different programming packages, blocking of certain channels, and many other functions. The compression and decompression of packetized video signals may be accomplished according to the Motion Picture Expert Group (MPEG) standards and the compression and decompression of audio signals may be accomplished according to the Motion Picture Expert Group (MPEG) standards, DOLBY DIGITAL® (or AC-3) standards, DTS or other known standards. The conventional STB therefore typically includes video and audio decoders in order to decompress the received compressed video and audio. The STB may output video and audio data to a number of destinations, including additional audio and video decoders, as well as ports, memories, and interface devices, such as a digital VHS (DVHS) interface. The STB may also send the same audio and video data to different destinations.
Currently, these STBs (or IRDs) are configured so as to interface with a specific network or system. For example, a DIRECTV® receiver cannot be used in a DISH Network® system, and vice versa. One problem is that each network has it own networking standard, including specific conditional access protocol, bitstream scrambling algorithms, transport format, and audio and video encoding and decoding standards to conform to. As the content provider community shrinks and corporations with dissimilar systems merge, the costs in merging two or more networks becomes a significant issue.
Assuming that such a merger results in a single surviving system, a problem remains with regard to transitioning the users of the now defunct system to the surviving system. For example, the equipment of the system that will no longer exist after the merger will become obsolete unless provisions are taken to make the equipment compatible with the surviving system prior to the transition. Furthermore, the equipment may also have to handle a transition scenario where multiple broadcast systems are active, and the equipment must therefore be capable of receiving and processing signals from both systems. In addition, during the transition period, both systems may still be active, with some channels being broadcast only on one system and other channels only on the other system.
The concepts of simulcrypt and multicrypt that have been devised for digital video broadcast (DVB) systems are not necessarily suitable solutions for the system transition scenarios described above. However, they are concepts that may be used in building equipment to handle the transition. The goal is to allow a single piece of equipment to receive content from multiple service providers. As defined in the digital video broadcast (DVB) environment, the same algorithm for the scrambling of bitstreams is used by simulcrypt systems, while for multicrypt systems, different algorithms can be used to scramble the bit streams for the different systems. In both multicrypt and simulcrypt systems, the same modulation subsystems, transport subsystems, as well as the same audio and video subsystems, are expected for the multiple service providers.
Accordingly, a need exists for a suitable apparatus and method for processing content signals received from a plurality of different, and possibly dissimilar, signal sources, such as different satellite networks, to thus enable a single STB to handle signals from multiple networks that may use different scrambling algorithms and different transport, audio and video subsystems.